The invention disclosed herein relates to apparatus for inserting documents or enclosures into envelopes, and more particularly to such apparatus which unfolds the envelope flap and feeds the enclosure or enclosures into the "flapped" envelope.
The mailing process involves a number of operations including feeding, assembly and insertion of mail items into an envelope, moistening the envelope flap, sealing the envelope, weighing the envelope, applying postage, etc. Automation of such operations typically includes moving an envelope into and through a station to complete the insertion operation. With respect to the document feeding operations, see, for example, U.S. Pat. Nos. 4,169,341 (Roether et al.), 4,570,923 (Hooper et al.), 4,619,101 (Havey, Jr., et al.), and 4,775,140 (Foster). The disclosures of those patents, which are assigned to the assignee of the present application, are hereby incorporated by reference. Frequently, rollers and belt conveyors are used to move the envelope within a station while the particular mailing operation is carried out.
As the throughput of modern mailing apparatus increases, envelope jamming has occurred more frequently requiring more frequent operator intervention and longer overall machine down time. In addition to the rate that the envelopes are handled, the size, design and weight of the envelopes have an effect on the jam frequency.
Typically, the inserting operation includes an envelope feeder and an envelope "flapper" which unfolds or "flaps" envelope flaps open so that documents may be inserted into the "flapped" envelope at a queuing station. such is the case with U.S. Pat. No. 4,775,140 noted above, which discloses a pivoting frame assembly to provide jam-clearing access to the envelope feed path through the envelope flapper. U.S. Pat. No. 5,081,825 (Mrozinski), assigned to the assignee of the present invention, also discloses a flapping and inserting apparatus which comprises jam-clearing access to the enclosure feed path and the upstream end of the queuing station.
Typically, the inserting apparatus includes a flapper that is suitable for flapping a limited variety of envelope types, or styles, appropriate for the particular use of the inserting apparatus. Problems generally occur because the gap between the flapper and the means for feeding the envelope past the flapper is fixed with little tolerance for handling a variety of envelopes. If the gap is too large for a particular type of envelope, it will pass by the flapper without having the flap opened. If the gap is too narrow, the flap of the envelope may jam or become crimped by the flapper.
Although it is known to adjust the gap between the flapper and the means for feeding the envelope, such an adjustment typically requires a service technician and includes a repositioning of the entire flapper. Furthermore, this becomes a more difficult and sensitive adjustment on inserting apparatus expected to handle envelopes of all sizes, designs and weights. For flappers extending the length of the envelope flap, adjustments in the gap are more sensitive to tolerance across the length of the flapper because problems such as jamming can occur anywhere along the entire length of the flapper. As a result, adjustments of the flapper position to correct the size of the gap can be repetitive and time consuming.